http://trac.sacrideo.us/wg/wiki/BracketsBraces shows the meaning
of square brackets and curly braces in my Scheme test suite, which
currently includes 45 implementations. Only Chibi and RScheme currently
do something special with braces; the other implementations treat them
as either synonyms for parentheses, lexical syntax errors, or identifier
characters.
--
A rose by any other name John Cowan
may smell as sweet, http://www.ccil.org/~cowan
but if you called it an onion cowan@xxxxxxxx
you'd get cooks very confused. --RMS